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| author | Vineet Gupta <vgupta@synopsys.com> | 2015-02-02 16:53:21 +0300 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2015-06-19 15:39:30 +0300 |
| commit | 8d0d56ba24d8d0b04bc9d9a7fbd1796d8966159f (patch) | |
| tree | 87dd235d9d6c2931e543bea091d5e47417a773a4 | |
| parent | 556cc1c5f528dcc87733920de17d61b6ebe8999d (diff) | |
| download | linux-8d0d56ba24d8d0b04bc9d9a7fbd1796d8966159f.tar.xz | |
ARC: [axs101] support early 8250 uart
Earlycon calculates UART clock as "BASE_BAUD * 16". In case of ARC
"BASE_BAUD" is calculated dynamically in runtime, basically it is an
alias to arc_early_base_baud(), which in turn just does
"arc_base_baud/16".
8250 UART on AXS/SDP board uses 33.3MHz clock source which is set in
"arc_base_baud" with this change.
Additional compatibility string "snps,arc-sdp" is introduced as well
because there're different flavours of AXS boards but they all share the
same motherboard and so it's possible to re-use the same code for
motherbord even if CPU daughterboard changes.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
| -rw-r--r-- | Documentation/devicetree/bindings/arc/axs101.txt | 2 | ||||
| -rw-r--r-- | arch/arc/boot/dts/axs101.dts | 4 | ||||
| -rw-r--r-- | arch/arc/kernel/devtree.c | 2 |
3 files changed, 5 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/arc/axs101.txt b/Documentation/devicetree/bindings/arc/axs101.txt index 568aa5f74de2..48290d5178b5 100644 --- a/Documentation/devicetree/bindings/arc/axs101.txt +++ b/Documentation/devicetree/bindings/arc/axs101.txt @@ -4,4 +4,4 @@ Synopsys DesignWare ARC Software Development Platforms Device Tree Bindings SDP Main Board with an AXC001 CPU Card hoisting ARC700 core in silicon Required root node properties: - - compatible = "snps,axs101"; + - compatible = "snps,axs101", "snps,arc-sdp"; diff --git a/arch/arc/boot/dts/axs101.dts b/arch/arc/boot/dts/axs101.dts index 6c3391da0e3b..3f9b0582e734 100644 --- a/arch/arc/boot/dts/axs101.dts +++ b/arch/arc/boot/dts/axs101.dts @@ -13,9 +13,9 @@ /include/ "axs10x_mb.dtsi" / { - compatible = "snps,axs101"; + compatible = "snps,axs101", "snps,arc-sdp"; chosen { - bootargs = "console=tty0 console=ttyS3,115200n8 consoleblank=0"; + bootargs = "earlycon=uart8250,mmio32,0xe0022000,115200n8 console=tty0 console=ttyS3,115200n8 consoleblank=0"; }; }; diff --git a/arch/arc/kernel/devtree.c b/arch/arc/kernel/devtree.c index e32b54abff51..f801d46dc087 100644 --- a/arch/arc/kernel/devtree.c +++ b/arch/arc/kernel/devtree.c @@ -32,6 +32,8 @@ static void __init arc_set_early_base_baud(unsigned long dt_root) if (of_flat_dt_is_compatible(dt_root, "abilis,arc-tb10x")) arc_base_baud = core_clk/3; + else if (of_flat_dt_is_compatible(dt_root, "snps,arc-sdp")) + arc_base_baud = 33333333; /* Fixed 33MHz clk */ else arc_base_baud = core_clk; } |